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1.
Godlewska P. Gerasymchuk Y. S. Tomachynskii L. A. Legendziewicz J. Hanuza J. 《Structural chemistry》2010,21(2):461-467
Room temperature Fourier transform IR and Raman spectra in the range 30–4000 cm−1 and 80–4000 cm−1 of Dy, Ho, Er and Lu phthalocyanide PcLn(OAc)-type complexes have been measured, respectively. The assignment of the bands
observed has been made on the literature data. The molecular structure of the PcLnX-type derivatives has been discussed on
the basis of the group theory taking into account the shape and number of the bands corresponding to the stretching and bending
vibrations of the LnN4O coordination polyhedron as well as whole PcLn(OAc) complex. 相似文献
2.
Jing Yang Ray L. Frost Wayde N. Martens 《Journal of Thermal Analysis and Calorimetry》2010,100(1):109-116
The transition of cubic indium hydroxide to cubic indium oxide has been studied by thermogravimetric analysis complimented
with hot-stage Raman spectroscopy. Thermal analysis shows the transition of In(OH)3 to In2O3 occurs at 219 °C. The structure and morphology of In(OH)3 synthesised using a soft chemical route at low temperatures was confirmed by X-ray diffraction and scanning electron microscopy.
A topotactical relationship exists between the micro/nano-cubes of In(OH)3 and In2O3. The Raman spectrum of In(OH)3 is characterised by an intense sharp band at 309 cm−1 attributed to ν1 In–O symmetric stretching mode, bands at 1137 and 1155 cm−1 attributed to In-OH δ deformation modes, bands at 3083, 3215, 3123 and 3262 cm−1 assigned to the OH stretching vibrations. Upon thermal treatment of In(OH)3, new Raman bands are observed at 125, 295, 488 and 615 cm−1 attributed to In2O3. Changes in the structure of In(OH)3 with thermal treatment is readily followed by hot-stage Raman spectroscopy. 相似文献
3.
The antimalarial agent mefloquine was investigated using Fourier transform near-infrared (FT NIR) Raman and FT IR spectroscopy.
The IR and Raman spectra were calculated with the help of density functional theory (DFT) and a very good agreement with the
experimental spectra was achieved. These DFT calculations were applied to unambiguously assign the prominent features in the
experimental vibrational spectra. The calculation of the potential energy distribution (PED) and the atomic displacements
provide further valuable insight into the molecular vibrations. The most prominent NIR Raman bands at 1,363 cm−1 and 1,434 cm−1 are due to C=C stretching (in the quinoline part of mefloquine) and CH2 wagging vibrations, while the most intense IR peaks at 1,314 cm−1; 1,147 cm−1; and 1,109 cm−1 mainly consist of ring breathings and δCH (quinoline); C–F stretchings; and asymmetric ring breathings, C–O stretching as
well as CH2 twisting/rockings located at the piperidine moiety. Since the active agent (mefloquine) is usually present in very low concentrations
within the biological samples, UV resonance Raman spectra of physiological solutions of mefloquine were recorded. By employing
the detailed non-resonant mode assignment it was also possible to unambiguously identify the resonantly enhanced modes at
1,619 cm−1, 1,603 cm−1 and 1,586 cm−1 in the UV Raman spectra as high symmetric C=C stretching vibrations in the quinoline part of mefloquine. These spectroscopic
results are important for the interpretation of upcoming in vitro and in vivo mefloquine target interaction experiments. 相似文献
4.
L. M. Babkov O. V. Gorshkova E. V. Gabrusyonok G. A. Puchkovskaya I. N. Khakimov 《Journal of Structural Chemistry》1995,36(5):739-746
Vibrational spectroscopy methods (IR absorption, Raman scattering, calculations) were used to study changes in molecular structures
of alkoxycyanobiphenyls during phase transitions. The spectra were measured in the 33–3500 cm−1 region at temperatures of 100–450 K. The temperature dependences of the IR bands that correspond to the noncharacteristic
vibrations of molecular fragments between the phenyl rings and the alkyl radicals point to the conformational polymorphism
of these molecules. An analysis of the Raman bands corresponding to the characteristic vibrations of the C−H bonds of alkyl
radicals [q(CH)], the C−H and C−C bonds of phenyl rings [q(CH) and Q(CC)], and the CN bonds of the cyano groups [Q(CN)] suggests
significant intermolecular interactions. The conformational lability and intermolecular interactions are associated with differences
in molecular packing in the substances of this homologous series.
Saratov State University. Institute of Solid State Physics, Rostov State University. Institute of Physics, Uzbekistan Academy
of Sciences. Samarkand State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 5, pp. 814–822, September–October, 1995.
Translated by I. Izvekova 相似文献
5.
Ar and Kr matrix effect on the geometry and Cl–H stretching (ν
s
(Cl–H)) and librational (ν
l
(Cl–H)) frequencies of the hydrogen-bonded complex Cl–H···NH3 are simulated within the framework of polarizable continuum model with integral equation formalism (IEF-PCM) at B3LYP and
MP2 levels of theory with the basis set 6-311++G(2df,2pd). Within the framework of B3LYP and IEF-PCM, the simulated gas phase,
Ar, and Kr matrix ν
s
(Cl–H) of the complex are 2140, 1684, and 1550 cm−1, respectively, which deviate from the experimental values (~2200, 1371, and 1218 cm−1) by −60, 313, and 332 cm−1. Within the framework of MP2 and IEF-PCM, the gas phase, Ar, and Kr matrix ν
s
(Cl–H) are calculated as 2366, 2037, and 1957 cm−1 by the harmonic approximation, and as 2177, 1876, and 1665 cm−1 by the full-dimensional anharmonic correction. The matrix effect modeling is of greater importance than the anharmonic correction
in accounting for the large experimental gas phase to Ar or Kr matrix shift of the ν
s
(Cl–H) (−829 or −982 cm−1). Our calculations do not support the assignment of the 733.8 and 736.9 cm−1 bands to the Ar and Kr matrix ν
l
(Cl–H). 相似文献
6.
Silver ions confined in the silver stearate Langmuir-Blodgett (L-B) films of 8-14 layers were elec-trochernically reduced into Ag clusters,which made the observation of well-ordered scanning tunneling microscope (STM) images of the films with molecular resolution.A hexagonal packing of the hydrophobic chains was obtained,which was superimposed on the two-dimensional Ag clusters of 2-3 nm m diameter.Furthermore,a (2×1) struc-time of the hexagonal packing was observed.It was attributed to a self-assembled structure of the hydrophilic surface of the L-B films through hydrogen bonding.The strong surface enhanced Raman scattering (SERS) effect of Ag clusters made it possible to record Raman spectra of two-layer steanc acid L-B films in the region of C-C stretching vibration frequencies The appearance of the bands at 1 128 0 and 1 100.7 cm-1,which correspond to the antisymmetric C-C stretching model of the acyl chains m the all-trans conformation and the C-C stretching model of the acyl chains in the gauche 相似文献
7.
Near-infrared and mid-infrared spectra of three tellurite minerals have been investigated. The structures and spectral properties
of copper bearing xocomecatlite and tlapallite are compared with an iron bearing rodalquilarite mineral. Two prominent bands
observed at 9,855 and 9,015 cm−1 are assigned to 2B1g → 2B2g and 2B1g → 2A1g transitions of Cu2+ ion in xocomecatlite. The cause of spectral distortion is the result of many cations of Ca, Pb, Cu and Zn in the tlapallite
mineral structure. Rodalquilarite is characterised by ferric ion absorption in the range 12,300–8,800 cm−1. Three water vibrational overtones are observed in xocomecatlite at 7,140, 7,075 and 6,935 cm−1 whereas in tlapallite bands are shifted to lower wavenumbers at 7,135, 7,080 and 6,830 cm−1. The complexity of rodalquilarite spectrum increases with the number of overlapping bands in the near-infrared. The observation
of intense absorption feature near 7,200 cm−1 confirms hydrogen bonding water molecules in xocomecatlite. Weak bands observed near 6,375 and 6,130 cm−1 in tellurites are attributed to the hydrogen bonding between (TeO3)2− and H2O. A number of overlapping bands at low wave numbers 4,800–4,000 cm−1 are caused by combinational modes of tellurite ion. (TeO3)2− stretching vibrations are characterised by three main absorptions at ~1,070, 780 and 665 cm−1.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
8.
Patel II Trevisan J Singh PB Nicholson CM Krishnan RK Matanhelia SS Martin FL 《Analytical and bioanalytical chemistry》2011,401(3):969-982
Vibrational spectroscopy techniques can be applied to identify a susceptibility-to-adenocarcinoma biochemical signature. A
sevenfold difference in incidence of prostate adenocarcinoma (CaP) remains apparent amongst populations of low- (e.g. India)
compared with high-risk (e.g. UK) regions, with migrant studies implicating environmental and/or lifestyle/dietary causative
factors. This study set out to determine the biospectroscopy-derived spectral differences between risk-associated cohorts
to CaP. Benign prostate tissues were obtained using transurethral resection from high-risk (n = 11, UK) and low-risk (n = 14, India) cohorts. Samples were analysed using attenuated total reflection Fourier-transform infrared (FTIR) spectroscopy,
FTIR microspectroscopy and Raman microspectroscopy. Spectra were subsequently processed within the biochemical cell region
(1,800−1–500 cm–1) employing principal component analysis (PCA) and linear discriminant analysis (LDA) to determine whether wavenumber–absorbance/intensity
relationships might reveal biochemical differences associated with region-specific susceptibility to CaP. PCA-LDA scores and
corresponding cluster vector plots identified pivotal segregating biomarkers as 1,582 cm−1 (Amide I/II trough); 1,551 cm−1 (Amide II); 1,667 cm−1 (Amide I); 1,080 cm−1 (DNA/RNA); 1,541 cm−1 (Amide II); 1,468 cm−1 (protein); 1,232 cm−1 (DNA); 1,003 cm−1 (phenylalanine); 1,632 cm−1 [right-hand side (RHS) Amide I] for glandular epithelium (P < 0.0001) and 1,663 cm−1 (Amide I); 1,624 cm−1 (RHS Amide I); 1,126 cm−1 (RNA); 1,761, 1,782, 1,497 cm−1 (RHS Amide II); 1,003 cm−1 (phenylalanine); and 1,624 cm−1 (RHS Amide I) for adjacent stroma (P < 0.0001). Primarily protein secondary structure variations were biomolecular markers responsible for cohort segregation
with DNA alterations exclusively located in the glandular epithelial layers. These biochemical differences may lend vital
insights into the aetiology of CaP. 相似文献
9.
We investigate effects of Co dopant concentration on the structure and low temperature Raman scattering properties in SrTi1−x
Co
x
O3 (x = 0.00, 0.10, 0.20, 0.30) nanoparticles prepared by sol–gel method. The dopant induced changes are studied by XRD, and Raman
scattering measurements. The results show an average particle size of about 20 nm depending on the Co content and the lattice
parameters decrease as increasing the Co content. In the Raman spectra, a broad structure in the region 100–500 cm−1 is almost absent and the peaks in the region 600–800 cm−1 show different weights with respect to SrTiO3, relating to structural changes. The anomalous change in the area ratio of Raman peaks as function of temperature suggests
a phase transition in our samples in the range of 110–130 K. These results indicate that the Co ion has replaced the site
of Ti in unit cell. This novel route also demonstrates the advantage of synthesizing the compound with low annealing temperature. 相似文献
10.
Graham A. Bowmaker Paul A. Kilmartin Graham A. Wright 《Journal of Solid State Electrochemistry》1999,3(3):163-171
Stable, yellow anodic films of parathiocyanogen (SCN)
x
were formed on a platinum electrode from 2.8 M KSCN in methanol at 45 °C at a constant current of 20–40 mA cm−2 for 15–30 min. Loosely bound orange crystals of a more amorphous character were removed by rinsing to leave an adherent yellow
film with sharp Raman bands under 647.1 nm laser excitation at 627 cm−1 (vCS), 1152 cm−1 and 1236–1261 cm−1 (vNN and vCN). The lack of electroactivity and short-lived photocurrents pointed to an insulating film at potentials up to 1.0 V (SHE).
At more positive potentials, longer-lasting photocurrents were obtained, consistent with breakdown of the insulating film.
XPS scans confirmed N:C:S ratios close to 1:1:1, with a deficiency of S of some 10% due to S lost as sulfate at the film surface.
Oxidation of SeCN− in neutral aqueous solution led to the formation of a less-stable orange paraselenocyanogen film with a Raman band at 1256–1267 cm−1, which decomposed within a day to grey selenium.
Received: 12 December 1997 / Accepted: 23 March 1998 相似文献
11.
Deuk Yong Lee Kyong-Ho Lee Myung-Hyun Lee Nam-Ihn Cho Bae-Yeon Kim 《Journal of Sol-Gel Science and Technology》2010,53(1):43-49
Ba1−x
Sr
x
TiO3(x = 0–0.5, BST) nanofibers with diameters of 150–210 nm were prepared by using electrospun BST/polyvinylpyrrolidone (PVP) composite
fibers by calcination for 2 h at temperatures in the range of 650–800 °C in air. The morphology and crystal structure of calcined
BST/PVP nanofibers were characterized as functions of calcination temperature and Sr content with an aid of XRD, FT-IR, and
TEM. Although several unknown XRD peaks were detected when the fibers were calcined at temperatures less than 750 °C, they
disappeared with increasing the temperature (above 750 °C) due to its thermal decomposition and complete reaction in the formation
of BST. In addition, the FT-IR studies of BST/PVP fibers revealed that the intensities of the O–H stretching vibration bands
(at 3430 and 1425 cm−1) became weaker with increasing the calcination temperature and a broad band at 540 cm−1, Ti–O vibration, appeared sharper and narrower after calcination above 750 °C due to the formation of metal oxide bonds.
However, no effect of Sr content on the crystal structure of the composites was detected. 相似文献
12.
Manuel Mora María Isabel López César Jiménez-Sanchidrián José Rafael Ruiz 《Journal of Sol-Gel Science and Technology》2010,55(1):59-65
Three different hydrotalcites were synthesized from magnesium ethoxide, and aluminium, gallium and indium acetylacetonate,
using the sol–gel technique. The colloid suspensions initially obtained were gelled and separated by centrifugation. XRD diffraction
patterns confirmed that all solids thus obtained possessed a hydrotalcite structure. The resulting hydrotalcites were characterized
by mid-infrared (MIR) and near-infrared (NIR) spectroscopies. The two types of spectra were found not to depend on the synthetic
medium or trivalent metal used and were thus quite similar. The MIR spectra for the three solids included a strong band at
3500–3000 cm−1 due to stretching vibrations of the different types of O–H groups in them. The signal at about 1370 cm−1 observed for all solids indicates that the sole interlayer anion present was carbonate. The NIR spectra exhibited the bands
for the first and second overtone of the O–H stretching vibration in addition to various combination bands. 相似文献
13.
Ramzi Zarrougui Mahmoud Dhahbi Daniel Lemordant 《Journal of solution chemistry》2010,39(10):1531-1548
The densities of binary mixtures of ethylammonium nitrate (EAN) ionic liquid (IL) and γ-butyrolactone (BL) have been measured over the entire range of concentrations at 293.15, 298.15, 303.15, 308.15, 313.15 and
318.15 K and under ambient pressure. Experimental densities were used to calculate excess molar volumes VmEV_{m}^{\mathrm{E}}, isobaric and excess isobaric expansion coefficients α and α
E. The excess molar volumes have both negative and positive values, while the excess isobaric expansion coefficients are negative
over the entire composition range. The VmEV_{m}^{\mathrm{E}} values have been fitted to the Redlich-Kister polynomial equation, and other volumetric properties such as the partial molar
volumes V
mi
, the excess partial molar volume VEmiV^{\mathrm{E}}_{mi} and the partial molar volumes at infinite dilution V¥miV^{\infty}_{mi} were calculated. The results have been interpreted in terms of dipole-dipole interactions, hydrogen bonds formation and structural
factors of these mixtures. The FT-Raman spectroscopy study of the intensity variations of some characteristic bands such as
the C=O stretching band at 1763 cm−1, C–O symmetric stretching band at 932 cm−1 and C–C stretching band at 872 cm−1 of BL has been undertaken. The solvation phenomenon is evidenced by the modifications of these band intensities due to the
presence of the IL ions. Moreover, the Raman spectroscopy corroborates the volumetric study. The average number of BL molecules
in the primary solvation shell of the ethylammonium cation lies between 3 and 4 depending on the temperature. 相似文献
14.
We investigate effects of Fe dopant concentration on the structure, as well as low temperature Raman scattering and electrical
transport properties in SrTi1−x
Fe
x
O3 (x = 0.00, 0.10, 0.20, 0.30, 0.40) nanoparticles prepared by sol-gel method. The results show an average particle size of powder
is about 30 nm, and the lattice parameters decrease as increasing the Fe content. In the Raman spectra, a broad structure
in the region 200–500 cm−1 is almost absent and the peaks in the region 600–800 cm−1 show different weights with respect to SrTiO3, relating to structural changes with increasing dopant concentration in conjunction with increasing grain boundary contribution
to the impedance. The abrupt change in Raman peak position as function of temperature suggests a phase transition in our samples
in the range of 110–150 K. These results indicate that the Fe ion has replaced the site of Ti in unit cell. These results
also demonstrate the feasibility of synthesizing the compound with low annealing temperature. 相似文献
15.
I. I. Grinval’d A. N. Artemov I. V. Bodrikov L. I. Bazhan I. Yu. Kalagaev 《Russian Journal of General Chemistry》2009,79(7):1487-1489
The IR spectra of complexes derived from conjugated arylalkenes and tricarbonylchromium, namely (stilbene)tricarbonylchromium
and (styrene)tricarbonylchromium, displayed three absorption bands instead of two expected in the region of carbonyl stretching
vibrations (1800–2000 cm−1). Additional absorption bands also appeared in the region corresponding to metal-π-fragment stretching vibrations (250–400
cm−1). These findings indicated additional interaction involving the central metal atom, carbonyl ligands, and aromatic π-system.
Such interaction increases mobility of the tricarbonylchromium fragment which may become capable of readily migrating from
one π-fragment to another under certain conditions. 相似文献
16.
The hydration of mesityl oxide (MOx) was investigated through a sequential quantum mechanics/molecular mechanics approach.
Emphasis was placed on the analysis of the role played by water in the MOx syn–anti equilibrium and the electronic absorption spectrum. Results for the structure of the MOx–water solution, free energy of solvation
and polarization effects are also reported. Our main conclusion was that in gas-phase and in low-polarity solvents, the MOx
exists dominantly in syn-form and in aqueous solution in anti-form. This conclusion was supported by Gibbs free energy calculations in gas phase and in-water by quantum mechanical calculations
with polarizable continuum model and thermodynamic perturbation theory in Monte Carlo simulations using a polarized MOx model.
The consideration of the in-water polarization of the MOx is very important to correctly describe the solute–solvent electrostatic
interaction. Our best estimate for the shift of the π–π* transition energy of MOx, when it changes from gas-phase to water solvent, shows a red-shift of −2,520 ± 90 cm−1, which is only 110 cm−1 (0.014 eV) below the experimental extrapolation of −2,410 ± 90 cm−1. This red-shift of around −2,500 cm−1 can be divided in two distinct and opposite contributions. One contribution is related to the syn → anti conformational change leading to a blue-shift of ~1,700 cm−1. Other contribution is the solvent effect on the electronic structure of the MOx leading to a red-shift of around −4,200 cm−1. Additionally, this red-shift caused by the solvent effect on the electronic structure can by composed by approximately 60 %
due to the electrostatic bulk effect, 10 % due to the explicit inclusion of the hydrogen-bonded water molecules and 30 % due
to the explicit inclusion of the nearest water molecules. 相似文献
17.
The basic copper arsenate mineral strashimirite Cu8(AsO4)4(OH)4·5H2O from two different localities has been studied by Raman spectroscopy and complemented by infrared spectroscopy. Two strashimirite mineral samples were obtained from the Czech (sample A) and Slovak (sample B) Republics. Two Raman bands for sample A are identified at 839 and 856 cm−1 and for sample B at 843 and 891 cm−1 are assigned to the ν1 (AsO43−) symmetric and the ν3 (AsO43−) antisymmetric stretching modes, respectively. The broad band for sample A centred upon 500 cm−1, resolved into component bands at 467, 497, 526 and 554 cm−1 and for sample B at 507 and 560 cm−1 include bands which are attributable to the ν4 (AsO43−) bending mode. In the Raman spectra, two bands (sample A) at 337 and 393 cm−1 and at 343 and 374 cm−1 for sample B are attributed to the ν2 (AsO43−) bending mode. The Raman spectrum of strashimirite sample A shows three resolved bands at 3450, 3488 and 3585 cm−1. The first two bands are attributed to water stretching vibrations whereas the band at 3585 cm−1 to OH stretching vibrations of the hydroxyl units. Two bands (3497 and 3444 cm−1) are observed in the Raman spectrum of B. A comparison is made of the Raman spectrum of strashimirite with the Raman spectra of other selected basic copper arsenates including olivenite, cornwallite, cornubite and clinoclase. 相似文献
18.
Controlled nanosized TiO2 particles of 4–10 nm were synthesized by a simple hydrolysis method followed by calcination at different temperatures. These
particles were investigated using X-ray diffraction (XRD), Photoacoustic/Fourier transform infrared (PA/FTIR) spectroscopy,
Raman spectroscopy and electron spin resonance (ESR) spectroscopy to understand their structural properties. X-ray diffraction
studies confirmed the anatase phase of the particles where as the PA/FTIR revealed the bands around 1,500 and 3,300 cm−1 due to –OH bands. ESR spectroscopic investigations carried out from 5 to 300 K indicated the presence of an ESR line at g = 2.00 emerging from radical species. It is significant to note that the intensity of the ESR line decreased as the particle
size increased. 相似文献
19.
Abstract
Cholesterol complexes with tri-n-butyl phosphate, tri-n-octylamine, N,N-dimethylacetamide, and cyclohexanone in benzene and toluene solutions were studied using conventional IR spectroscopy. The spectra were recorded in the region of fundamental OH stretching (3,700–3,100 cm−1) at 298 K. The experimental spectra were resolved into bands corresponding to the cholesterol monomer and particular oligomeric and complex species. The formation constants of complexes were determined from the-least squares plots of the linearized expressions of Bjerrum’s formation function. The stoichiometry of complexes was also identified in this way. The identification of the particular resolved bands was performed from their location, and from the dependence of their intensity on the cholesterol monomer and free base concentration. 相似文献20.
Di Giambattista L Pozzi D Grimaldi P Gaudenzi S Morrone S Castellano AC 《Analytical and bioanalytical chemistry》2011,399(8):2771-2778
Fourier transform infrared spectroscopy in attenuated total reflection can be used to discriminate the necrotic from the apoptotic
cell death in a tumoral T cell line irradiated by a UV source able to induce both apoptosis and necrosis. Using Jurkat cells
as the model system, significant spectral differences in the irradiated cells vs. time were observed in the lipid–proteins
ratio absorbance band at 1,397 cm−1 and in lactic acid IR band at 1,122 cm−1; these spectral features are inversely correlated with the percentage of apoptotic cells assessed by flow cytometry. From
the analysis of second derivatives in the IR spectral region between 1,800 and 900 cm−1, we have detected two significant spectral changes: the first centered at 1,621 cm−1 by analyzing the components of the amide I band and the second centered at 1,069 cm−1 due to C–O stretching vibration of the DNA backbone sensitive to the dehydrated state of DNA; these identified differences
in the intracellular biomolecules have been allowed to monitor the necrotic process. The variations in the spectral data set
have been identified by the Kruskal–Wallis test and confirmed by the hierarchical cluster analysis. 相似文献